Lime mobility and soil acidity correction can be influenced by liming management and the quantity and quality of soil organic matter. Acidity neutralization in function of the lime incoporation and surface liming was evaluated in a red Latosol (Oxisol) under different antecedent vegetation covers (eucalyptus, forest, pasture and pine). The study was carried out from November 2002 to January 2003 at the Soil Science Department of the Lavras Federal University. After 30 days of incubation of soils with lime, the […]

Artificial changes in the properties of a soil contaminated with hexachlorobenzene were promoted in order to study the effects on the microbial community and the degradation of this compound. The soil samples were flooded or enriched with organic material or lime under laboratory conditions. The microbial activity and density as well as the total (mineralization) or partial hexachlorobenzene degradation (transformation into metabolites) were analyzed. The mineralization of 14C-hexachlorobenzene was analyzed by adding a 14C-hexachlorobenzene solution to soil samples, capturing the […]

A considerable part of eucalypt plantations in Brazil grows on low-fertility soils for which fertilization techniques and nutrient cycling processes are important to elevate and maintain the forest production. The response of these plantations to nitrogen fertilization has been relatively low, indicating that the soil has been capable of supplying part of the plant demand. Microbial biomass N is considered a readily available fraction, but little is known about the biotic and abiotic factors that affect its dynamics in eucalypt […]

The sorption of herbicides to soil is a process determinant of its dynamics in the environment. For weakly polar compounds such as acetochlor, organic matter represents the main sorbent in soil. The goal of this study was to evaluate the sorption of acetochlor on soil samples, humic acids and humin from an “Argissolo Vermelho distrófico” (PVd-Paleudult) under no-till and conventional tillage systems. Sorption isotherms were carried out at room temperature and the herbicide concentration was determined by high performance liquid […]

Biossolid has been used in agriculture as nutrient source and to improve soil physical attributes. The effect of biossolid on the aggregate stability and soil penetration resistance of a medium texture Oxisol (LVd) and clayey Oxisol (LVef) in Jaboticabal (SP) were evaluated. Dry biosolid mass was applied with a harrow at rates of 0.0, 25.0, 47.5, 50.0 Mg ha-1, incorporated at 0.1 m depth before sowing the maize. Samples were collected in the fifth year after the maize harvest from the 0.0-0.1, 0.1-0.2, […]

Organic matter can reduce P adsorption/precipitation (PA/P) by: release of organic acids which compete for phosphate adsorption sites; trough the formation of P- compounds in the soil solution; and by building complexes with Fe and Al and thus decreasing PA/P. The aim of this study was to evaluate the PA/P in Oxisols, by addition of organic acids: citric (CA), oxalic (OA), salicylic (SA), and humic acids (HA). An amount of 2.5 cm3 samples of a clayey Red Latosol (Rodic Hapluxtox) and […]

From 1920 on, Ferralsols of the Planalto Médio region in the State of Rio Grande do Sul, Brazil, originally under forest vegetation, were converted into agricultural land, while the same soils under grassland were converted in the 1960-ies. Thereafter, chemical soil properties were affected by intense cropping, mainly of soybean and corn. To evaluate how the time of agricultural land use affected two Ferralsols in the Fortaleza dos Valos county, State of Rio Grande do Sul, pedon samples of a […]

Physical, chemical and mineralogical characteristics of soils from the meadows of Sousa (Paraíba State – Brazil) were studied, as well as the effect of alkaline and alkaline-earthy cations on humic substance stability. Furthermore, criteria of environmental distinction used by the small farmers and different forms of land use in the studied region were identified. Profiles from the classes Ustifluvents (Neossolo Flúvico), Haplustalfs (Luvissolo), Natrustalfs (Planossolo nátrico), and Usterts (Vertissolo crómico) were therefore selected, sampled and analyzed. Besides sodium, magnesium also […]

This study was conducted at the Experimental Station of the Faculdade de Engenharia (UNESP), Ilha Solteira County, Mato Grosso do Sul State, Brazil, with the aim of evaluating chemical modifications in a Red Latosol under cerrado, subjected to different use and management systems. A completely randomized design with six treatments and 10 replications was used. The treatments of use and management were: no-tillage with annual crops, conventional system with annual crops, minimum tillage with annual crops, native vegetation (cerrado), pasture, […]

Aluminum (Al) is one of the most abundant elements in weight in Brazilian soils, found in different minerals and forms. Considering the lack of information about its participation in the physical behavior of soil, the present study aimed to evaluate the relationship between the mineralogy of the clay fraction, different forms of Al and physical attributes of different soils. Disturbed and undisturbed samples of A and B horizons of representative soils from the South and Campos das Vertentes physiographic regions […]